package com.musiklegal;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Collections;
import java.util.Map;
import java.util.Stack;
import java.util.WeakHashMap;

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.util.Log;
import android.widget.ImageView;

public class ImageLoader {
    
    //the simplest in-memory cache implementation. This should be replaced with something like SoftReference or BitmapOptions.inPurgeable(since 1.6)
    private Map<String, Bitmap> cache=Collections.synchronizedMap(new WeakHashMap<String, Bitmap>());
    
    private File cacheDir;
    
    
    public ImageLoader(){
        //Make the background thead low priority. This way it will not affect the UI performance
        photoLoaderThread.setPriority(Thread.NORM_PRIORITY-1);
        
        cacheDir=new File(MusikLegal.cacheFolder);
        
        
        
    }
    
    final int stub_id=R.drawable.header;
    public void DisplayImage(String url, Activity activity, ImageView imageView,String file)
    {
    	
	        if(cache.containsKey(file))
	            imageView.setImageBitmap(cache.get(file));
	        else
	        {
	        	imageView.setImageResource(stub_id);
	            queuePhoto(url, activity, imageView,file);
	            
	        }    
    	
    	
    }
        
    private void queuePhoto(String url, Activity activity, ImageView imageView,String nama)
    {
        //This ImageView may be used for other images before. So there may be some old tasks in the queue. We need to discard them. 
        photosQueue.Clean(imageView);
        PhotoToLoad p=new PhotoToLoad(url, imageView, nama);
        synchronized(photosQueue.photosToLoad){
            photosQueue.photosToLoad.push(p);
            photosQueue.photosToLoad.notifyAll();
        }
        
        //start thread if it's not started yet
        if(photoLoaderThread.getState()==Thread.State.NEW)
            photoLoaderThread.start();
    }
    
    private Bitmap getBitmap(String url,String name) 
    {
        //I identify images by hashcode. Not a perfect solution, good for the demo.
        
        File f= new File(cacheDir,name);//new File(cacheDir, name+".jpg");
        
        //from SD cache
        Bitmap b = decodeFile(f);
        if(b!=null)
        {
        		
        	return b;
        }
       
        //from web
        
            Bitmap bitmap=null;
            InputStream is;
			try {
				is = new URL(url).openStream();
				 OutputStream os = new FileOutputStream(f);
		            Utils.CopyStream(is, os);
		            os.close();
		            is.close();
		            bitmap = decodeFile(f);
		            return bitmap;
			} catch (MalformedURLException e) {
				Log.e("Decode picture", e.getMessage());
				e.printStackTrace();
				return null;
			
			} catch (IOException e) {
				Log.e("Decode picture", e.getMessage());
				e.printStackTrace();
				return null;
			}
           
        
    }

    //decodes image and scales it to reduce memory consumption
    private Bitmap decodeFile(File f){
        try {
            //decode image size
            BitmapFactory.Options o = new BitmapFactory.Options();
            o.inPurgeable=true;
            o.inJustDecodeBounds = true;
            BitmapFactory.decodeStream(new FileInputStream(f),null,o);
            
            //Find the correct scale value. It should be the power of 2.
            final int REQUIRED_SIZE=60;
            int width_tmp=o.outWidth, height_tmp=o.outHeight;
            int scale=1;
            while(true){
                if(width_tmp/2<REQUIRED_SIZE || height_tmp/2<REQUIRED_SIZE)
                    break;
                width_tmp/=2;
                height_tmp/=2;
                scale++;
            }
            
            //decode with inSampleSize
            BitmapFactory.Options o2 = new BitmapFactory.Options();
            o2.inSampleSize=scale;
            return BitmapFactory.decodeStream(new FileInputStream(f), null, o2);
        } catch (FileNotFoundException e) {}
        return null;
    }
    
    //Task for the queue
    private class PhotoToLoad
    {
        public String url,filename;
        public ImageView imageView;
        public PhotoToLoad(String u, ImageView i, String name){
            url=u; 
            imageView=i;
            filename=name;
        }
    }
    
    PhotosQueue photosQueue=new PhotosQueue();
    
    public void stopThread()
    {
        photoLoaderThread.interrupt();
    }
    
    //stores list of photos to download
    class PhotosQueue
    {
        private Stack<PhotoToLoad> photosToLoad=new Stack<PhotoToLoad>();
        
        //removes all instances of this ImageView
        public void Clean(ImageView image)
        {
            for(int j=0 ;j<photosToLoad.size();){
                if(j<photosToLoad.size() && photosToLoad.get(j).imageView==image)
                    photosToLoad.remove(j);
                else
                    ++j;
            }
        }
    }
    
    class PhotosLoader extends Thread {
        public void run() {
            try {
                while(true)
                {
                    //thread waits until there are any images to load in the queue
                    if(photosQueue.photosToLoad.size()==0)
                        synchronized(photosQueue.photosToLoad){
                            photosQueue.photosToLoad.wait();
                        }
                    if(photosQueue.photosToLoad.size()!=0)
                    {
                        PhotoToLoad photoToLoad;
                        synchronized(photosQueue.photosToLoad){
                            photoToLoad=photosQueue.photosToLoad.pop();
                        }
                        Bitmap bmp=getBitmap(photoToLoad.url,photoToLoad.filename);
                        cache.put(photoToLoad.filename, bmp);

                        if(((String)photoToLoad.imageView.getTag()).equals(photoToLoad.url)){
                            BitmapDisplayer bd=new BitmapDisplayer(bmp, photoToLoad.imageView);
                            Activity a=(Activity)photoToLoad.imageView.getContext();
                            a.runOnUiThread(bd);
                        }
                    }
                    if(Thread.interrupted())
                        break;
                }
            } catch (InterruptedException e) {
                //allow thread to exit
            }
            catch(Exception e)
            {
            	
            }
        }
    }
    
    PhotosLoader photoLoaderThread=new PhotosLoader();
    
    //Used to display bitmap in the UI thread
    class BitmapDisplayer implements Runnable
    {
        Bitmap bitmap;
        ImageView imageView;
        public BitmapDisplayer(Bitmap b, ImageView i){bitmap=b;imageView=i;}
        public void run()
        {
            if(bitmap!=null)
                imageView.setImageBitmap(bitmap);
            else
                imageView.setImageResource(stub_id);
        }
    }
    
    public void clearMemory()
    {
    	stopThread();
    	cache.clear();
    	System.gc();
    }

    public static void clearCache() {
        //clear memory cache
        File fc=new File(MusikLegal.cacheFolder);
       
        //clear SD cache
        File[] files=fc.listFiles();
        for(File f:files)
            f.delete();
    }

}
